Path Antenna Reflection Coefficient Issue

sem
sem Altair Community Member
edited October 2020 in Community Q&A

Hello

 

I design a phased array patch antenna that has pin fed architecture.

I have 2 issues with the design:

1. These is  an error with some of the regions: 'setting ambiguous,: Unable to merge medium'

2. When i try to add additional excitation wave guide ports, the new ports reflection coefficient is 1

 

What can be the reason for these issues?

Attached the design files.

Thanks in advance.

 

Unable to find an attachment - read this blog

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Answers

  • Mel
    Mel Altair Community Member
    edited May 2020

    1. This happened becauses you have cylinders (feed pins) going through the dielectric. Their region settings were initially probably solid PEC. When you Union them with the dielectric CADFEKO does not know what the intended region should be, either PEC or dielectric. You have to check if CADFEKO made the right chose for you. As long as the surface of the cylinders are PEC, the inside region can be set to PEC or dielectric.

    2. Did you send the correct model? The reflection coefficients of the 5 ports are seen below, they are not 1.

    Just double check the dimensions of the inner vs outer cylinders of the feeds. The OUT file shows they are presently 133 Ohm

    ' Characteristic impedance:      ( 1.33385E+02 +j 0.00000E+00) Ohm'

    image.png

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